The growth of plants is dependent on the synthesis of polysaccharides, especially, cellulose in cell walls. Innumerable methods and compositions have been proposed and/or developed to enhance the synthesis of these polysaccharides and thereby promote plant growth. Over the years, much of this development has focused on applying plant growth regulators (PGRs), such as auxins, cytokinins, gibberellins and brassinolides, to plants. Vitamin K and derivatives thereof have also been considered for use as a plant growth regulator as taught by Iino et al. in U.S. Pat. No. 4,764,201. However, field results using PGRs has, at best, been mixed. Further, PGRs, such as the derivatives of vitamin K proposed by Iino et al., are cost-prohibitive for practical applications. More recently, researchers are also considering genetic manipulation and related techniques to alter or otherwise enhance the growth patterns of plants. At present, many of these techniques are not yet applicable to field production and are typically limited to a specific type of plant.
Whether using a plant growth regulator or a genetically altered plant, any number of agronomically suitable additives, adjuvants and/or phytocatalysts are applied to the plants to support or enhance plant growth, including: fertilizers containing elements such as nitrogen, phosphorus, potassium, elevated carbon dioxide, hydrogen peroxide, iron and manganese; secondary nutrients such as sources of sulfur, calcium, and magnesium; micronutrients, such as boron, cobalt, copper, molybdenum, zinc, nickel; water soluble carbohydrates such as sucrose, fructose and glucose as described in U.S. Pat. No. 5,549,729; and various alkyl glucosides as described in U.S. Pat. No. 5,958,104.
Several of the phytocatalysts are particularly important, such as iron, manganese and an ammoniacal nitrogen source such as ammonium. However, it is known that high doses of these phytocatalyst nutrients are lethal to plants because the plants are not able to metabolize the nutrients at a sufficient rate. For example, it is known that, under conventional conditions of plant culture, ammonium is phytotoxic to plants at high concentrations as described by Robert M. Devlin et al., Photosynthesis, pp. 270-277 (Van Nostrand Reinhold Co. 1971). Devlin et al. found that a high concentration of ammonium elicits a plant response akin to various nutrient deficiencies. Further, ammonium ions are known to inhibit photophosphorylation and subsequent carbon dioxide fixation and, at very high concentrations, to impair photosynthesis in intact leaves.
Since high concentrations of ammonium reduce plant growth, the amount of ammonium used is typically limited to less than one third of the total source of nitrogen. See, Roy A. Larson, Introduction to Floriculture, 2d. Edition, p. 464 (Academic Press 1992). The recommended optimal nitrate-N concentrations are between 100 to 199 ppm for most horticultural applications. See, Id. and Vic Ball, Ball RedBook, 15th Edition, p. 246 (Geo J. Ball 1991). The generally accepted upper limit for nitrogen fertilizer is between about 300 ppm to 400 ppm. Concentrations above this range are considered toxic to plants. Thus, applying ammonium to treat plants and facilitate plant growth has until now been limited to low concentrations. Methods and formulations for safening high concentrations of manganese with alkyl glycosides are disclosed by A. Nonomura in U.S. patent application Ser. No. 09/448,345, filed on Nov. 23, 1999 and are incorporated herein by reference.